1. Field of the Invention
The present invention relates to a door-stop device for vehicles, of the type comprising: a base structure carrying a pair of rollers that turn about respective axes which are parallel to one another and are elastically pushed against one another; and a metal tie rod having a pair of rolling surfaces set opposite to one another, on which the above-mentioned rollers act, said rolling surfaces presenting at least one positioning notch designed to be engaged by one of said rollers to define a position of stable retention of the door.
2. State of the Art
One of the problems of the door-stop devices of the type indicated above lies in the fact that these devices, during the movement of opening and closing of the door, present an intrinsic noisiness due to the rolling of the rollers on the corresponding rolling surfaces of the tie rod. Automobile manufacturers set very strict limits on the maximum noise level admitted for such devices. For example, door-stop devices that produce noise levels higher than 52 dB are frequently not considered acceptable.
Although numerous solutions have been adopted to reduce the noise levels of the door-stop devices in question, as yet a definitive solution to the problem has not been found.
The aim of the present invention is to provide an improved door-stop device that enables a reduction in the noise levels as compared to known devices, at the same time without this involving an increase in the production cost.
According to the present invention, the above purpose is achieved by a door-stop device having the characteristics that form the subject of the main claim.
A door-stop device for vehicles comprises: a base structure (12) carrying a pair of rollers (1, 2) that turn about respective axes which are parallel to one another and are elastically pushed against one another; and a metal tie rod (14) having a pair of rolling surfaces (26, 28) set opposite to one another, on which the above-mentioned rollers (1, 2) act, said rolling surfaces (26, 28) presenting at least one positioning notch (32) designed to be engaged by one of said rollers (1, 2) to define a position of stable retention of the door.
The aforesaid positioning notch (32) presents: an arched central portion having a radius of curvature Ra=(10 to 15) R1, where R1 is the radius of the corresponding roller (1); a pair of arched lateral portions with a radius of curvature Rb=(1.1 to 1.8) R1, where the aforesaid central portion has an extension, in the direction of the longitudinal axis of the tie rod, A=(0.15 to 0.30) R1 (FIG. 2).